Millican
suspension system for automobiles

ABSTRACT

A (HYDRAULIC SUSPENSION SYSTEM FOR STABILIZING THE BODY STRUCTURE OF MOTOR VEHICLES, ESPECIALLY PASSENGER AUTOMOBILES, AND WHICH) WHEEL SUSPENSION SYSTEM FOR MOTOR VEHICLES, ESPECIALLY PASSENGER AUTOMOBILES AND INCLUDING UPPER AND LOWER SUSPENSION LINKS PIVOTALLY COUPLING THE FRONT WHEELS TO THE FRAME. COUPLED BETWEEN THE LINKS IS A COIL SPRING. THE SUSPENSION SYSTEM IS SEMIAUTOMATICALLY CONTROLLED BY A SYSTEM OF HYDRAULIC CYLINDERS AND PISTONS, THE VALVES OF WHICH ARE ACTIVATED BY ELECTRICAL CIRCUITS WHICH ARE OPENED AND CLOSED BY THE MOTION OF THE VEHICLE BODY OCCASIONED BY ROAD SURFACE IRREGULARITIES AND LATERAL MOMENTUM DUE TO DEVIATIONS IN THE DIRECTION OF TRAVEL, SUCH AS AT CURVES AND ANGULAR TURNS IN THE ROAD.

April 17, 1973 J. c. MILLICAN Re. 27,623

SUSPENSION SYSTEM FOR AUTOMOBILES 3 Sheets-Sheet L Original Filed Jan.31, 1969 Fig.|

INVENTOR Joel C. Millicun BY Q01 fflwao ATTORNEY A ril 17, 1973 J. c.MILLICAN 27,523

SUSPEN3 ION SYSTEM FOR AUTOMOBILES Origifial Filed Jan. 31, 1969 3Sheets-Sheet 2 INVENTOR Joel C. Millicon ATTORNEY April 17, 1973 J. c.MILLICAN SUSPENSION SYSTEM FOR AUTOMOBILES Original Filed Jan. 31, 19695 Sheets-Sheet 3 6 INVENTOR Joel C. Millicon Fig.6

lLp-

Fig.5

ATTORNEY United States Patent Olhce Re-issued Apr. 17, 1973 Matterenclosed in heavy brackets appears in the original patent but forms nopart of this reissue specification; matter printed in italics indicatesthe additions made by reissue.

ABSTRACT OF THE DISCLOSURE A [hydraulic suspension system forstabilizing the body structure of motor vehicles, especially passengerautomobiles, and which] wheel suspension system for motor vehicles,especially passenger automobiles and including upper and lowersuspension links pivotally coupling the front wheels to the frame.Coupled between the links is a coil spring. The suspension system issemiautomatically controlled by a system of hydraulic cylinders andpistons, the valves of which are activated by electrical circuits whichare opened and closed by the motion of the vehicle body occasioned byroad surface irregularities and lateral momentum due to deviations inthe direction of travel, such as at curves and angular turns in theroad.

SUMMARY This invention relates to a suspension system and to astabilizing system for motor vehicles, and it has particular referenceto a system of hydraulic cylinders and pistons for controlling thesuspension system of the vehicle.

One object of the invention is to provide a wheel suspension system formotor vehicles and comprising a frame and upper and lower suspensionlinks pivotally coupling a wheel to the frame. Coupled between the linksis a resilient means which in the embodiment disclosed is a coil spring.

[A prime] Another object of the invention resides in the provision of anarrangement of hydraulic cylinders whose pistons are actuated throughthe automatic opening and closing of electrical circuits having aplurality of solenoid valves connected therein and through linkagesconnecting the cylinders directly to the conventional suspension systemof the vehicle whereby the body thereof can resist excessive verticaland lateral motion imparted thereto through road surface irregularitiesand directional deviations.

A further object of the invention is that of providing a vehiclesuspension system which is calculated to minimize the hazard of upset intraversing curves, or in passing on roadways in which speed is sometimesa necessary factor, and to enable the vehicle to be safely controlledunder such conditions.

Yet another object of the invention is that of providing a hydraulicsystem by which the spring assembly of the vehicle is relieved of asubstantial portion of the normal load by reducing the shocks generallyencountered on uneven road surfaces, and to afford automatic means,through an electrical circuit, for actuating the system whereby tomaintain maximum balance of the vehicle body in cooperation with theconventional suspension system.

While the foregoing objects are paramount, other and lesser objects willbecome apparent as the description proceeds when considered inconnection with the appended drawings wherein:

FIG. 1 is a schematic illustration of a [conventional] front endsuspension system [embodying] of the inventiion, including the severalhydraulic cylinders and pistons, and the eleectrical circuits actuatingthese elements, the entire system being shown in neutral positions.

FIG. 2 is an enlarged sectional view of one of the hydraulic controlvalve units in which the plug is shown in neutral position.

FIG. 3 is another enlarged sectional view, similar to FIG. 2, in whichthe plug is in its lowermost position, the fluid flow being indicated byarrows.

FIG. 4 is yet another enlarged sectional view similar to FIGS. 2 and 3,the plug being shown in its uppermost position, the fluid flow beingindicated by arrows.

FIG. 5 is a fragmentary plan view of a vehicle frame and front endsuspension system embodying one aspect of the invention and showing apair of torsion bars having linkage with a pair of hydraulic cylinderand piston units controlled by a mercury switch in an electricalcircuit.

FIG. 6 is a transverse sectional view, on line 6-6 of FIG. 5, andschematically illustrating the hydraulic system by which the torsionbars are controlled, including the mercury switch and solenoids in theelectrical circuits, all in neutral positions.

FIG. 7 is a view, in partial section, of a front end suspension systemwith a floating upper arm assembly, the hydraulic assembly and mercuryswitch being shown fragmentarily in neutral positions.

[The invention is primarily concerned with the provision of a hydraulicsystem whereby to augment the conventional suspension devices common tomost standard motor vehicles, especially passenger vehicles. Suchconventional apparatus consists of an independent coil springsuspension, two types of which are illustrated generally in FIGS. 1 and7 of the drawings] In FIG. 1 the front wheels 10 are attached to thevehicle frame 11 by upper and lower linkages 12 and 13 which haverespective pivotal connections 14 and 15 to the frame 11. Coil springs16 are arranged between the linkages 12 and 13. In FIG. 7 the wheels 10are attached to the frame 11 by lower linkage arms 17, which arepivotally connected to the frame 11 at 18. A cross member 19 is pivotedintermediate its ends to the frame 11 at 20 and the coil springs 16 areseated at their lower ends on the arms 17 while their upper ends areengaged by seats formed on the outer ends of the cross member 19. [Whilethe two types of suspension devices described are most commonly used,other structures are well known and are similarly composed] [Theinvention seeks to provide] Also provided is a hydraulic system designedto minimize the pressures normaly exerted on the spring system and tomaterially resist the vertical and lateral movements of the vehicle bodyencountered in varying road conditions and speed, traversing curves,passing other vehicles, and the like, and minimizing the hazard ofupset.

One embodiment of the [invention] hydraulic system and the manner inwhich it is supported is shown in FIG. 1. [and] As illustrated thehydraulic system: primarily comprises a pair of hydraulic cylinders 21,having pistons 22 therein, one of such units being mounted on each ofthe upper linkages 12,. the latter having depending cylindricalreceptacles 23 formed therewith to receive the upper ends of the coilsprings 16 seated in cavitationsformed in the lower surfaces ofpiston-like members 24 on the lower ends of the rods 25 of the hydraulicpistons 22 in the cylinders 21, the lower ends of the spring 16 beingseated on the lower linkages 13. As will become apparent, the pistons 22will control the action of the springs 16 with the cooperation of otherelements which will be presently described.

Re. 27,623 v The schematic illustration in FIG. 1 shows a fluidreservoir 26 having a flow conduit 27 connected to a pump 28, which maybe driven by the vehicle engine, and a return conduit 29 connected toflow conduits 30 and 31 for directing hydraulic fluid to a pair oftwo-way valves 32 and 33, respectively, which alternately control thefluid flow to the cylinders 21, attached to the top links 12, throughconduits 34 and 35 connected, respectively, to the upper and lower endsof the cylinders 21.

The valves 32 and 33 are identical in structure, having a cylindricalhousing 36 with alternate inlet and outlet ports 37 and 38 into whichthe conduits 34 and 35 are respectively connected, as shown in FIG. 1,and in greater detail in FIGS. 2, 3 and 4 in which the pistons or plugs39 are shown in their respective positions in the housings 36, thearrows indicating the direction of flow through the several ports. Aninlet port 40 and two outlet ports 41 and 42 are provided in the housing36, and these ports are offset in relation to the ports 37 and 38. Oneof the conduits 30 and 31 is connected to the port 40 in each valvehousing 36 as inlet flow conductors. Connected to the respective outletports 41 and 42 are branch conduits 43 and 44 of a conduit 45 which isconnected to the reservoir 26 whereby fluid is returned to the latterfrom the valves 36.

The piston or plug 39 of each valve 33 or 34 is formed with a pair ofcircumferential grooves 46 and 47 each providing an annular fluidpassage within the housing 36 capable of alternately effectingcommunication between the inlet and outlet ports 37 and 38 and the inletport 40 and the port 41 or 42, as indicated in FIGS. 3 and 4. The plug39 is shown in neutral position in FIG. 2 in which all of the ports 40',41 and 42 are covered. In FIG. 3 the ports 37 and 38 are open to theports 40 and 42, respectively, and in FIG. 4 the ports 37 and 38 areopen to the ports 40 and 41. The arrows in each of these views indicatethe direction of flow through the valves.

Each of the plugs 39 has an integral stem 48 on one end and a stem 49 onthe other, each operatively extending through its respective end of thehousing 36 and having a suitable packing ring 50 therearound. Each stem48 and 49 has a solenoid 51 attached to its outer end for shifting theplug 39 from one of its operative positions to the other when theelectrical circuits 52 and 53 therefor are closed through a mercuryswitch 54 connected therein, as shown in FIG. 1.

The mercury switch 54 may be of conventional design, having electrodes55 and 56 connected into the circuits 52 and 53 and an electrode 57, asshown in FIG. 1, which is connected into a conductor 58 to the source 59and the ground 60. A manual switch 61 is provided in the conductor 58.The electrodes 55 and 56 are so arranged as to be contacted by the fluidmercury 62 in the switch 54, as indicated in broken lines in FIG. 1,depending upon the lateral inclinations of the frame 11.

The modified structure shown in FIG. 7 has the same function as thatshown in FIG. 1, differing primarily in the use of the rockingcrossmem-ber 19 instead of the upper linkage 12 of the structure shownin FIG. 1. The cylinders 21, with their pistons 22 therein, arepivotally supported on brackets 63 rigidly attached to each side of thevehicle frame 11. The rod or stem 25 of each piston 22 has its free endpivoted at 64 to the crossmember 19. The conduits 34 and 35 areconnected into the cylinders 21 in the same manner as that shown in FIG.1, and the flow of hydraulic fluid is controlled by the same type ofvalve system and the mercury switch 54.

A further modification of the application of the improved hydraulicsystem is shown in FIGS. and 6 in which a different type of suspensionsystem is employed but which is of generally conventional design. Thewheels are connected to the frame 11 by upper and lower linkage plates65 and 66, respectively, pivoted at 67 and 68 to brackets 69 and 70attached to the frame 11.

for connecting the [upper and] lower linkage [plates 65 and] plate 66 t0bracket 69.

The structure shown in FIGS. 5 and 6 has embodied therein a pair oftorsion rods of bars 72 arranged along each side member of the frame 11,as best shown in FIG. 5, and have their rearmost ends secured thereto bybrackets 73 in which the members 72 are secured against rotation by pins74 arranged through the brackets 73. The bars 72 are pivotally supportedby brackets 75 on the frame 11 at their forward ends, and are integrallyattached intermediate their ends to one end of a pair of linkage arms 76whose opposite ends are pivotally connected at 77 to clevises 78 on thelower ends of the rods 25 of the pistons 22 in the cylinders 21, shownin FIGS. 5 and 6, which are secured by brackets 79 attached to acrossmember 80 arranged transversely of the frame 11 rearwardly of thefront wheel assembly.

OPERATION The valves 32 and 33 and the pistons 22 of the cylinders 21are shown in FIG. 1 in the neutral positions, as when the vehicle isstanding. The mercury switch 54 is open and the electrical circuits 52and 53 of the solenoids 51 are inoperative. When the vehicle is movingthe rocking motion imparted to the frame 11 will cause the mercury 62 inthe switch 54 to shift and make contact between one of the electrodes 55or 56 and the electrode 57 to actuate the respective valve 32 or 33whereby to admit hydraulic fluid to the respective cylinders 21.

The operation of the valves 32 and 33 is best illustrated in FIGS. 2, 3and 4. In FIG. 2 the plug 39 is shown in its neutral position, all ofthe ports being closed. FIG. 3 shows the plug 39 in its lowermostposition, having been acted upon by the upper solenoid 51, to cause thefluid to flow through the port 38, the lower groove 47, and out throughthe port 42 to the reservoir 26, as indicated by the arrows. At the sametime the fluid enters through the port 40 and out through the port 37.

FIG. 4 shows the reverse movement of the fluid, the plug 39 being in itsuppermost position, having been acted upon by the lower solenoid 51, tocause the fluid to enter through the port 37 and out through the port41, and thence to the reservoir 26, while the ports 38 and 40 are openedto admit the fluid from the pump 28 to the bottom of the affectedcylinder 21. The pistons 22 in the cylinders 21 are operative in eitherdirection and are thus capable of resisting or cushioning the shockimparted by the rebound of the springs 16.

The arrangement of the several elements shown and described may bemodified to suit the structural arrangement of suspension system towhich the invention may be applied.

I claim:

1. In a hydraulic control mechanism for a suspension system for motorvehicles having a frame, upper and lower suspension links pivotallyconnecting the front Wheels to said frame, and biasing means separatingsaid links, in combination, a hydraulic cylinder, having a pistontherein, mounted on each of said upper links, the said pistons beingoperatively connected to said biasing means for resisting the actionthereof, a two-way valve having fluid conduits connected thereincommunicating with each of said cylinders on each side of the pistontherein whereby to control the movement thereof, a fluid reservoirhaving fluid inlet and outlet conduits connecting the same to saidtwo-way valves, a solenoid on each end of each of said valves foroperating the same to intermittently and alternately change thedirection of fluid flow therethrough, an electrical circuit for saidsolenoids and a mercury switch in said circuit and a fluid pump forcirculating hydraulic fluid through said valves.

2. The structure of claim 1, the said biasing means comprising coilsprings.

3. The structure of claim 2, each of said pistons in coir nnlinrlmmhavinn a stem avhanr'lino Iv-law said (viinders, and having a cavitatedmember on its lowermost end, the said coil springs having their upperends seated in said cavitated member.

4. The structure of claim 1, the said two-way valves having acylindrical housing and a plug operating in said housing, each of saidplugs having a plurality of circumferential grooves therein definingannular fluid passages, a stem on each end of said plugs whereby saidsolenoids are connected to said plugs to actuate the same in alternatedirections in said cylinders.

5. A wheel suspension system for motor vehicles, comprising:

a frame,

upper and lower suspension links pivotally coupling a wheel to saidframe, and

a coil spring coupled between said upper and lower links,

said upper and lower links including upper and lower mounting meansrespectively for supporting said coil spring between said upper andlower links in a manner to locate the axis of said coil spring in agenerally vertical position,

said upper mounting means having no pivotal movement relative to saidupper link,

said lower mounting means having no pivotal movement relative to saidlower link.

6. The suspension system of claim 5, wherein: one of said mounting meanscomprises hydraulic means coupled to one of said links for minimizingpressure exerted on said coil spring.

7. A front wheel suspension system for motor vehicles, comprising: i

a frame,

6 two pairs of upper and lower suspension links, each of which pivotallycouples a front wheel of a motor vehicle to said frame, and

a coil spring coupled between said upper and lower links of each of saidpairs, said upper and lower links of each pair including upper and lowermounting means respectively for supporting its coil spring between saidupper and lower links,

each upper mounting means being free from pivotal movement relative toits upper link,

each lower mounting means being free from pivotal movement relative toits lower link.

8. The suspension system of claim 7 wherein: the upper mounting means ofeach pair of links comprises hydraulic means for minimizing pressureexerted on its coil spring.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS PHILIP GOODMAN, Primary Examiner US. Cl. X.R.

